The X-Men square off against the newly revived Mimic, who has once more imitated all the X-Men's powers and abilities. Although the group of mutant heroes attack Mimic as a team, they prove to be no match against the combined force of Mimic's abilities. With the X-Men soundly defeated, Mimic proclaims that nobody can stop him.

We then turn the clock back to earlier when the X-Men have just returned from San Rico following their battle against El Tigre with an injured Angel. Back in his right mind, Angel apologizes to Cyclops for accusing him of purposely injuring him during the fight, realizing that it was really just an accident. This doesn't go far in eliminating Cyclops' guilt over the accident, as it is the one thing he's feared most of all, his powers harming someone close to him. The Professor orders Angel to be given immediate medical attention so that the X-Men are ready to face any menace that might arise in the near future.

Meanwhile, at Metro College, Jean Grey watches the athletic performances put on by Ted Roberts and afterword, Ted begins to express his growing feeling toward her. However, before the conversation can go any further, they are drawn to the sound of an explosion in the chemistry lab. Going to investigate, they find that Calvin Rankin was involved and he was unharmed by the accidental blast. However, the blast has revived Mimic's lost memories and powers.

This is not the only potential threat to the X-Men, as the evil Puppet Master is turning his attentions toward the X-Men's leader. Having learned of the Professor's existence from his sometimes ally the Mad Thinker, the Puppet Master begins to craft a special puppet of the X-Men's leader in the hopes of taking control of Xavier. However, when he attempts to use the special radioactive clay puppet, he finds that some sort of psychic feedback prevents him from taking control. The Puppet Master then decides to focus his attention on someone else who doesn't have these defenses.

Back at the X-Mansion, the Puppet Master's attempts to take control of the Professor do not go unnoticed, and he cautions his students about the attempted intrusion as the group is finishing a new component to Cerebro that will allow the Professor to better pinpoint any mutant menaces that might threaten the Earth. Sensing a potential threat from evil mutants, the Professor sends out his astral form to try and locate other mutants to join in their cause. He contacts Quicksilver and the Scarlet Witch who are in Romania, where they have taken a brief sabbatical from their membership in the Avengers believing that returning to their homeland will restore their fading powers. Although this seems to be working, when the Professor contacts them, they decline an offer to join the X-Men, pledging their loyalty toward the Avengers.

Later, while Bobby and Hank are out on a date with Vera and Zelda, the girls become interested in a bank robbery when they hear the alarms going off. Deciding to go into action, the two mutants sneak off and change into the Beast and Iceman to try and catch the crooks. They happen on the crooks a little too late as they have just been rounded up by Spider-Man. Xavier contacts them mentally and asks Beast and Iceman to offer Spider-Man membership in the X-Men. Spider-Man, having just failed an initiation with the Avengers, wearily declines before speeding off. Hank and Bobby change back to their civilian guises before Vera and Zelda come back from the robbery scene.

The next afternoon, the team goes to visit Metro College to pick up Jean when they are confronted by Mimic who reveals to them that his powers and memories have returned. Mimic asks to join the X-Men, and the group agrees to take him aboard. As they bring him back to the X-Mansion, Mimic begins duplicating their powers again. The group is unaware that they are being monitored by the Puppet Master who sees Mimic's joining with the group the perfect opportunity to strike.

While the other X-Men are presented with new costumes designed by Jean, Mimic is suddenly put under the control of the Puppet Master, leading to the battle between him and the X-Men that began at the start of this issue. The Professor, detecting that the Puppet Master is controlling Mimic, tries to get Mimic to resist the Puppet Master's influence. Mimic refuses to believe it, and goes off for fresh air. However he falls under the Puppet Master's sway again.

The Professor sends Cyclops, Beast, Iceman, and Marvel Girl off to confront the Puppet Master. Arriving at the villain's hideout, they have to defend themselves from an attack from the Puppet Master's "Defender", a gigantic robot that can fend off the X-Men's power. Back at the X-Mansion, Angel is well enough to get back on his feet but still cannot fly and the Professor has no choice but to send him out to help his teammates.

By the time Warren arrives, the other X-Men are caught in a stalemate against the Puppet Master. They have defeated his Defender, but the Puppet Master has brought Mimic to his base and is about to force him to destroy the X-Men. Angel steps in and knocks the puppet out of the Puppet Master's hands, freeing Mimic from their foes control. While the X-Men are checking on Warren, the Puppet Master escapes. The group notices that Mimic looks like a man condemned, their assessment is correct as Mimic has now come to realize that his powers are not really his own, but stolen from others and wonders if perhaps he has a place anywhere on Earth.

Notes

This issue is reprinted in many other comics and books, see references for more info.[2]

Jean Grey redesigns the groups costumes in this issue.

The Puppet Master reveals that he knows Professor X is the secret leader of the X-Men.